1. Field of the Invention
The present invention relates to a stereoscopic X-ray imaging apparatus.
2. Description of the Related Art
A stereoscopic X-ray imaging apparatus has an advantage of being capable of recognizing an anteroposterior relationship of a plurality of blood vessels. The stereoscopic X-ray imaging apparatus is configured to avoid unnecessary radiation exposure for an object (subject). Japanese Patent Application Laid-Open No. 2011-72369 discloses a configuration in which a three-dimensional position of a biopsy region is calculated based on two X-ray images obtained by stereoscopic imaging. Based on the calculated three-dimensional position of the biopsy region and a stereoscopic angle of a radiation source, a new X-ray radiation field is calculated. Japanese Patent Application Laid-Open No. 2010-233875 discloses a configuration in which an X-ray radiation field is controlled by a collimator to stay within a predetermined range. Japanese Patent Application Laid-Open No. 2010-115270 discloses a configuration in which a plurality of slits, through which an X-ray passes, is two-dimensionally formed in a collimator, and a size and a position of the plurality of slits are controlled.
In the X-ray imaging apparatus according to the related art having a stationary X-ray source (X-ray focus) and a stationary X-ray sensor, a position of each of the right and left X-ray sources for stereoscopic imaging is clear. Therefore, it is not necessary to distinguish between the radiation fields of the right and left X-ray sources. However, in an X-ray imaging apparatus having an X-ray source movable relative to an X-ray sensor, a three-dimensional positional relationship between the X-ray source and the X-ray sensor may not always be clear. For this reason, especially in stereoscopic X-ray imaging, it is necessary to set an appropriate angle of convergence and avoid the unnecessary radiation exposure due to a difference between the right and left X-ray radiation fields. Thus, a unit for appropriately and conveniently adjusting the positional relationship between the right and left X-ray sources is necessary for performing the effective stereoscopic X-ray imaging.